title: Control of human filarial vector, Culex quinquefasciatus Say 1823 (Diptera: Culicidae) through bioactive fraction of Cayratia trifolia leaf.
abstract: OBJECTIVE
  To investigate the mosquito larvicidal activity of Cayratia trifolia (L.) Domin (Vitaceae: Vitales) (C. trifolia) which is distributed in many parts of India with medicinal properties as vector control is facing threat due to the emergence of resistance to synthetic insecticides.
  
  
  METHODS
  Young and mature leaves of C. trifolia were investigated for larvicidal activity against 3rd instars larvae of Culex quinquefasciatus in different seasons throughout the year. The active fractions were extracted using six different solvents in a non-polar to polar fashion viz petroleum-ether, benzene, chloroform: methanol (1:1 v/v), acetone, absolute alcohol and distilled water. Dose dependent mortality was recorded against each solvent extract. Determination of LD50 and LD90 were executed through log-probit analysis using the most bioactive fraction. The fluctuations in mortality were statistically co-related through ANOVA analyses concerning different seasons and types of leaves as random variables. Justification of larvicidal activity was established through student's t-test. Costing effects were evaluated on the non-target water fauna under laboratory conditions. Thin layer chromatographic techniques were performed for phytochemical analysis and categorization of chemical personality of the active fractions using the most effective solvent extract following standard methods.
  
  
  RESULTS
  Significant variations in mortality rate were noted with respect to the type of leaves (mature and senescence), concentration of leaf extract and between seasons. The water extract among all the solvent extracts was found to induce cent percent mortality at 50 mg/L in test mosquito species within 24 h with a LD50 and LD90 value of 10.70 mg/L and 27.64 mg/L respectively. No significant mortality was recorded in non-target water population. Chromatographic analyses of the water extract revealed the presence of steroids, triterpene glycosides, essential oil, phenolics and diterpenes as secondary phytochemicals.
  
  
  CONCLUSIONS
  Water extract of C. trifolia leaf promised as a cost effective and potent larvicidal agent against Culex quinquefasciatus.
authors.affiliation: Mosquito and Microbiology Research Units, Parasitology Laboratory, Department of Zoology, The University of Burdwan, Burdwan-713104, West Bengal, India.
authors.forename: Sumanta
authors.initials: S
authors.lastname: Chakraborty
authors.forename: Someshwar
authors.initials: S
authors.lastname: Singha
authors.forename: Kuntal
authors.initials: K
authors.lastname: Bhattacharya
authors.forename: Goutam
authors.initials: G
authors.lastname: Chandra
mesh_terms: D000818:Animals; D001681:Biological Assay; D003465:Culex / Q000187:drug effects*; D006801:Humans; D007194:India; D007306:Insecticides / Q000302:isolation & purification / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D007928:Lethal Dose 50; D009032:Mosquito Control / Q000379:methods; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D016019:Survival Analysis; D027844:Vitaceae / Q000737:chemistry*
chemical_list: D007306:Insecticides; D010936:Plant Extracts
keywords: Cayratia trifolia; Culex quinquefasciatus; Larvicidal; Phytochemical analyses